Efanesoctocog Alfa Prophylaxis for Patients with Severe Hemophilia A.

BACKGROUND: Efanesoctocog alfa provides high sustained factor VIII activity by overcoming the von Willebrand factor-imposed half-life ceiling. The efficacy, safety, and pharmacokinetics of efanesoctocog alfa for prophylaxis and treatment of bleeding episodes in previously treated patients with severe hemophilia A are unclear. METHODS: We conducted a phase 3 study involving patients 12 years of age or older with severe hemophilia A. In group A, patients received once-weekly prophylaxis with efanesoctocog alfa (50 IU per kilogram of body weight) for 52 weeks. In group B, patients received on-demand treatment with efanesoctocog alfa for 26 weeks, followed by once-weekly prophylaxis with efanesoctocog alfa for 26 weeks. The primary end point was the mean annualized bleeding rate in group A; the key secondary end point was an intrapatient comparison of the annualized bleeding rate during prophylaxis in group A with the rate during prestudy factor VIII prophylaxis. Additional end points included treatment of bleeding episodes, safety, pharmacokinetics, and changes in physical health, pain, and joint health. RESULTS: In group A (133 patients), the median annualized bleeding rate was 0 (interquartile range, 0 to 1.04), and the estimated mean annualized bleeding rate was 0.71 (95% confidence interval [CI], 0.52 to 0.97). The mean annualized bleeding rate decreased from 2.96 (95% CI, 2.00 to 4.37) to 0.69 (95% CI, 0.43 to 1.11), a finding that showed superiority over prestudy factor VIII prophylaxis (P<0.001). A total of 26 patients were enrolled in group B. In the overall population, nearly all bleeding episodes (97%) resolved with one injection of efanesoctocog alfa. Weekly prophylaxis with efanesoctocog alfa provided mean factor VIII activity of more than 40 IU per deciliter for the majority of the week and of 15 IU per deciliter at day 7. Prophylaxis with efanesoctocog alfa for 52 weeks (group A) improved physical health (P<0.001), pain intensity (P = 0.03), and joint health (P = 0.01). In the overall study population, efanesoctocog alfa had an acceptable side-effect profile, and the development of inhibitors to factor VIII was not detected. CONCLUSIONS: In patients with severe hemophilia A, once-weekly efanesoctocog alfa provided superior bleeding prevention to prestudy prophylaxis, normal to near-normal factor VIII activity, and improvements in physical health, pain, and joint health. (Funded by Sanofi and Sobi; XTEND-1 ClinicalTrials.gov number, NCT04161495.).

Phase 1-2 Trial of AAVS3 Gene Therapy in Patients with Hemophilia B.

BACKGROUND: FLT180a (verbrinacogene setparvovec) is a liver-directed adeno-associated virus (AAV) gene therapy that uses a synthetic capsid and a gain-of-function protein to normalize factor IX levels in patients with hemophilia B. METHODS: In this multicenter, open-label, phase 1-2 trial, we assessed the safety and efficacy of varying doses of FLT180a in patients with severe or moderately severe hemophilia B (factor IX level, ≤2% of normal value). All the patients received glucocorticoids with or without tacrolimus for immunosuppression to decrease the risk of vector-related immune responses. After 26 weeks, patients were enrolled in a long-term follow-up study. The primary end points were safety and efficacy, as assessed by factor IX levels at week 26. RESULTS: Ten patients received one of four FLT180a doses of vector genomes (vg) per kilogram of body weight: 3.84×1011 vg, 6.40×1011 vg, 8.32×1011 vg, or 1.28×1012 vg. After receiving the infusion, all the patients had dose-dependent increases in factor IX levels. At a median follow-up of 27.2 months (range, 19.1 to 42.4), sustained factor IX activity was observed in all the patients except one, who resumed factor IX prophylaxis. As of the data-cutoff date (September 20, 2021), five patients had normal factor IX levels (range, 51 to 78%), three patients had levels from 23 to 43%, and one had a level of 260%. Of the reported adverse events, approximately 10% were related to FLT180a and 24% to immunosuppression. Increases in liver aminotransferase levels were the most common FLT180a-related adverse events. Late increases in aminotransferase levels occurred in patients who had received prolonged tacrolimus beyond the glucocorticoid taper. A serious adverse event of arteriovenous fistula thrombosis occurred in the patient with high factor IX levels. CONCLUSIONS: Sustained factor IX levels in the normal range were observed with low doses of FLT180a but necessitated immunosuppression with glucocorticoids with or without tacrolimus. (Funded by Freeline Therapeutics; ClinicalTrials.gov numbers, NCT03369444 and NCT03641703; EudraCT numbers, 2017-000852-24 and 2017-005080-40.).

Current and emerging gene therapies for haemophilia A and B.

INTRODUCTION: After decades of stumbling clinical development, the first gene therapies for haemophilia A and B have been commercialized and have normalized factor (F)VIII and factor (F)IX levels in some individuals in the long term. Several other clinical programs testing adeno-associated viral (AAV) vector gene therapy are at various stages of clinical testing. DISCUSSION: Multiyear follow-up in phase 1/2 and 3 studies showed long-term and sometimes curative but widely variable and unpredictable efficacy. Liver toxicities, mostly low-grade, occur in the 1st year in at least some individuals in all haemophilia A and B trials and are poorly understood. Wide variability and unpredictability of outcome and slow decline of FVIII levels are a major disadvantage because immune responses to AAV vectors preclude repeat dosing, which otherwise could improve suboptimal or restore declining expression, while overexpression may predispose to thrombosis. Long-term safety outcomes will need lifelong monitoring because AAV vectors infused at high doses integrate into chromosomes at rates that raise questions about potential oncogenicity and necessitate vigilance. Alternative gene transfer systems employing gene editing and/or non-viral vectors are under development and promise to overcome some limitations of the current state of the art for both haemophilia A and B. CONCLUSIONS: AAV gene therapies for haemophilia have now become new treatment options but not universal cures. AAV is a powerful but imperfect gene transfer platform. Biobetter FVIII transgenes may help solve some problems plaguing gene therapy for haemophilia A. Addressing variability and unpredictability of efficacy, and delivery of gene therapy to ineligible patient subgroups may require different gene transfer systems, most of which are not ready for clinical translation yet but bring innovations needed to overcome the current limitations of gene therapy.

A new population pharmacokinetic model for recombinant factor IX-Fc fusion concentrate including young children with haemophilia B.

AIMS: Recombinant factor IX Fc fusion protein (rFIX-Fc) is an extended half-life factor concentrate administered to haemophilia B patients. So far, a population pharmacokinetic (PK) model has only been published for patients aged ≥12 years. The aim was to externally evaluate the predictive performance of the published rFIX-Fc population PK model for patients of all ages and develop a model that describes rFIX-Fc PK using real-world data. METHODS: We collected prospective and retrospective data from patients with haemophilia B treated with rFIX-Fc and included in the OPTI-CLOT TARGET study (NTR7523) or United Kindom (UK)-EHL Outcomes Registry (NCT02938156). Predictive performance was assessed by comparing predicted with observed FIX activity levels. A new population PK model was constructed using nonlinear mixed-effects modelling. RESULTS: Real-world data were obtained from 37 patients (median age: 16 years, range 2-71) of whom 14 were aged <12 years. Observed FIX activity levels were significantly higher than levels predicted using the published model, with a median prediction error of -48.8%. The new model showed a lower median prediction error (3.4%) and better described rFIX-Fc PK, especially for children aged <12 years. In the new model, an increase in age was correlated with a decrease in clearance (P < .01). CONCLUSIONS: The published population PK model significantly underpredicted FIX activity levels. The new model better describes rFIX-Fc PK, especially for children aged <12 years. This study underlines the necessity to strive for representative population PK models, thereby avoiding extrapolation outside the studied population.

Cases of less-than-expected FVIII activity in previously treated patients during post-marketing surveillance of N8-GP.

INTRODUCTION: Turoctocog alfa pegol (N8-GP) is a glycoPEGylated, extended half-life (EHL), human recombinant factor VIII (FVIII) approved for the treatment and prevention of bleeding episodes in patients with haemophilia A. Since its launch in August 2019, > 800 patients have been treated worldwide. AIM: To present data from identified post-marketing cases of less-than-expected FVIII activity in previously treated patients (PTPs) without inhibitors after switching to N8-GP. METHODS: The post-marketing safety database was searched using keywords such as 'coagulation FVIII level decreased'. Identified cases reported prior to 13 October 2021 were included in this report. Cases in which patients had FVIII inhibitors were excluded. RESULTS: Here we report 14 cases of less-than-expected FVIII activity. Details varied greatly amongst the cases. At presentation, FVIII activity ranged from 1% (15 min post-dose) to 51% (2 days post-dose). Seven patients experienced bleeding episodes after switching to N8-GP with heterogeneity in bleeding presentations. Six out of seven patients who were tested for anti-PEG IgG and/or IgM antibodies were positive. In all known cases, FVIII activity returned to the expected range when switched to an alternative FVIII replacement product. CONCLUSION: In conclusion, the 14 reported cases of less-than-expected FVIII activity, without presence of detectable FVIII inhibitors, presented with heterogenous characteristics, and wide variations in FVIII activity and anti-PEG antibody titre. FVIII activity returned to the expected range after switching to alternative FVIII products. In line with WFH guidelines, monitoring of FVIII activity can ensure FVIII activity in the expected range. The safety surveillance of N8-GP continues.

The humanistic and economic burden of problem joints for children and adults with moderate or severe haemophilia A: Analysis of the CHESS population studies.

INTRODUCTION: Adequate prophylactic treatment and physical activity improve joint health and clinical outcomes for people with haemophilia A (HA). However, non-clinical joint-related burden of moderate (MHA) and severe (SHA) HA has not been well characterised. AIM: To quantify the joint health-related humanistic and economic burden of MHA and SHA in Europe. METHODS: A retrospective analysis of the cross-sectional CHESS population studies using a patient-centric measure of joint health (problem joints, PJs: chronic joint pain and/or limited range of movement due to compromised joint integrity with or without persistent bleeding) was conducted. Descriptive statistics summarised health-related quality of life (HRQoL), work productivity/activity impairment and costs by number of PJs (0, 1 or ≥2) and HA severity. RESULTS: A total of 1171 patients were included from CHESS-II (n = 468) and CHESS-PAEDs (n = 703). In both studies, 41 and 59% of patients had MHA and SHA, respectively. Prevalence of ≥2 PJs was similar with MHA and SHA (CHESS-II: 23 and 26%; CHESS-PAEDs: 4 and 3%, respectively). HRQoL was worse with an increasing number of PJs (CHESS-II: .81 vs. .66 with 0 and ≥2 PJs, respectively, for MHA; .79 vs. .51 for SHA; CHESS-PAEDs: .64 vs. .26 and .72 vs. .14). Total costs increased with increasing PJs regardless of severity in CHESS-II (€2923 vs. €22,536 with 0 and ≥2 PJs, respectively, for MHA; €11,022 vs. €27,098 for SHA) and CHESS-PAEDs (€6222 vs. €11,043 for MHA; €4457 vs. €14,039 for SHA). CONCLUSION: Presence of PJs was associated with a substantial humanistic and economic burden on patients with MHA or SHA across the lifespan.

Emicizumab prophylaxis in haemophilia A with inhibitors: Three years follow-up from the UK Haemophilia Centre Doctors' Organisation (UKHCDO).

INTRODUCTION: The UK National Haemophilia Database (NHD) collects data from all UK persons with haemophilia A with inhibitors (PwHA-I). It is well-placed to investigate patient selection, clinical outcomes, drug safety and other issues not addressed in clinical trials of emicizumab. AIMS: To determine safety, bleeding outcomes and early effects on joint health of emicizumab prophylaxis in a large, unselected cohort using national registry and patient reported Haemtrack (HT) data between 01 January 2018 and 30 September 2021. METHODS: Prospectively collected bleeding outcomes were analysed in people with ≥6 months emicizumab HT data and compared with previous treatment if available. Change in paired Haemophilia Joint Health Scores (HJHS) were analysed in a subgroup. Adverse events (AEs) reports were collected and adjudicated centrally. RESULTS: This analysis includes 117 PwHA-I. Mean annualised bleeding rate (ABR) was .32 (95% CI, .18; .39) over a median 42 months treatment with emicizumab. Within-person comparison (n = 74) demonstrated an 89% reduction in ABR after switching to emicizumab and an increase in zero treated bleed rate from 45 to 88% (p < .01). In a subgroup of 37 people, total HJHS improved in 36%, remained stable in 46% and deteriorated in 18%, with a median (IQR) within-person change of -2.0 (-9, 1.5) (p = .04). Three arterial thrombotic events were reported, two possibly drug related. Other AEs were generally non-severe and usually limited to early treatment, included cutaneous reactions (3.6%), headaches (1.4%), nausea (2.8%) and arthralgia (1.4%). CONCLUSIONS: Emicizumab prophylaxis is associated with sustained low bleeding rates and was generally well-tolerated in people with haemophilia A and inhibitors.

Humanistic burden of problem joints for children and adults with haemophilia.

INTRODUCTION: The "problem joint" (PJ) concept was developed to address patient-centric needs for a more holistic assessment of joint morbidity for people with haemophilia (PwH). AIM: To quantify the humanistic burden of PJs in PwH to further support validation of the PJ outcome measure. METHODS: Multivariable regression models evaluated the relationship between PJs and health-related quality of life (HRQoL, EQ-5D-5L) and overall work productivity loss (WPL) using data from the 'Cost of HaEmophilia: a Socioeconomic Survey' population studies (adults: CHESS II, CHESS US+; children/adolescents: CHESS-Paeds). Covariates included were haemophilia severity, age, comorbidities and education. RESULTS: The CHESS II sample included 292 and 134 PwH for HRQoL and WPL analyses, mean age 38.6 years (39% ≥1 PJ, 61% none). CHESS US+ included 345 and 239 PwH for HRQoL and WPL, mean age 35 years (43% ≥1 PJ, 57% none). CHESS-Paeds included 198 PwH aged 4-17 (HRQoL only), mean age 11.5 years (19% ≥1 PJ, 81% none). In CHESS II and CHESS US+, presence of PJs was associated with worse HRQoL (Both p < .001). Few CHESS-Paeds participants had PJs, with no significant correlation with HRQoL. In CHESS II, upper body PJs were significantly correlated to WPL (p < .05). In CHESS US+, having ≥1 PJ or upper and lower body PJs were significantly correlated to WPL (vs. none; both p < .05). CONCLUSION: This study has shown a meaningful burden of PJs on PwH, which should be considered in clinical and health policy assessments of joint health.

COVID-19 coagulopathy - what should we treat?

NEW FINDINGS: What is the topic of this review? Overview of the coagulation abnormalities, including elevated D-dimers widely reported with COVID-19, often labelled as COVID coagulopathy. What advances does it highlight? The review highlights the changes in bronchoalveolar haemostasis due to apoptosis of alveolar cells, which contributes to acute lung injury and acute respiratory distress syndrome; the pathophysiological mechanisms, including endothelial dysfunction and damage responsible for thrombosis of pulmonary microcirculation and potential contribution to the hypoxaemia of COVID-19 acute lung injury; and changes in coagulation proteins responsible for the hypercoagulability and increased risk of thrombosis in other venous and arterial beds. The rationale for anticoagulation and fibrinolytic therapies is detailed, and potential confounders that might have led to less than expected improvement in the various randomised controlled trials are considered. ABSTRACT: Coronavirus disease 19 (COVID-19) causes acute lung injury with diffuse alveolar damage, alveolar-capillary barrier disruption, thrombin generation and alveolar fibrin deposition. Clinically, hypoxaemia is associated with preserved lung compliance early in the disease, suggesting the lack of excessive fluid accumulation typical of other lung injuries. Notably, autopsy studies demonstrate infection of the endothelium with extensive capillary thrombosis distinct from the embolic thrombi in pulmonary arteries. The inflammatory thrombosis in pulmonary vasculature secondary to endothelial infection and dysfunction appears to contribute to hypoxaemia. This is associated with elevated D-dimers and acquired hypercoagulability with an increased risk of deep vein thrombosis. Hypercoagulability is secondary to elevated plasma tissue factor levels, von Willebrand factor, fibrinogen, reduced ADAMTS-13 with platelet activation and inhibition of fibrinolysis. Multi-platform randomised controlled studies of systemic therapeutic anticoagulation with unfractionated and low molecular mass heparins demonstrated a survival benefit over standard care with full-dose anticoagulation in patients with non-severe disease who require supplemental oxygen, but not in severe disease requiring ventilatory support. Late intervention and the heterogeneous nature of enrolled patients can potentially explain the apparent lack of benefit in severe disease. Improvement in oxygenation has been demonstrated with intravenous fibrinolytics in small studies. Inhaled anticoagulants, thrombolytic agents and non-specific proteolytic drugs in clinical trials for decreasing alveolar fibrin deposition might benefit early disease. Essentially, COVID-19 is a multi-system disorder with pulmonary vascular inflammatory thrombosis that requires an interdisciplinary approach to combination therapies addressing both inflammation and intravascular thrombosis or alveolar fibrin deposits to improve outcomes.

Gene therapy: Practical aspects of implementation.

The first wave of gene therapies for haemophilia submitted for regulatory review utilize a liver-directed approach in which a functional gene copy of factor VIII (FVIII) or factor IX (FIX) is packaged inside a recombinant adeno-associated viral vector (rAAV). Following a single treatment event, these particles are taken up into liver cells, where the rAAV uncoats and delivers the DNA to the nucleus of the cell, where genetic elements that accompany the gene allow for efficient expression and secretion of FVIII or FIX protein into the plasma. An immune response to the vector capsid has been manifest by elevations in common liver enzymes that must be diligently followed postinfusion for weeks and months afterward and if signs of toxicity appear, will trigger a course of immunosuppression. Despite this, the studies have shown that this works in the great majority of individuals and the immunosuppression course is either avoided or short-lived for many. Optimal outcomes in the haemophilia population will be dependent on proper screening assessment and maintenance of liver health prior to consideration of gene therapy, close short-term follow up and implementation of immunomodulatory strategies to identify and manage liver toxicity and preserve durable transgene expression. This review proposes best practices to assist clinical teams with overcoming the challenges this platform of therapy poses to the traditional clinical care models and infrastructure within the haemophilia treatment centres (HTCs) who will be coordinating the patient's journey through this potentially transformative therapy.

Clinical outcomes after joint surgery in patients on turoctocog alfa pegol (N8-GP) prophylaxis: A post hoc analysis.

INTRODUCTION: Joint damage in haemophilia often requires surgical correction. However, the surgery effect on bleeding rates and other clinical joint outcomes can be unclear. AIM: To investigate the effects of joint surgery on joint annualized bleeding rates (JABRs) and physical health outcomes in patients with haemophilia A undergoing N8-GP prophylaxis. METHODS: Patients in the pathfinder 2 trial received N8-GP prophylaxis, enrolling in the pathfinder 3 trial for indicated surgery. Patients returned to pathfinder 2 post-surgery, continuing N8-GP prophylaxis until end-of-trial. JABRs were calculated from bleeding across all joints for pre-surgery (immediately before surgery) and post-surgery (to pathfinder 2 study end) periods. Joint-health-related outcomes were derived from patient records. RESULTS: Data (41 joint surgeries; n = 30) were analysed statistically using datamining and descriptively. Pre-surgery mean JABR was higher in patients who later were operated than in 146 non-operated patients (p = .004). In operated patients, mean JABR decreased from 1.33 pre-surgery to .37 post-surgery (p = .011). In all but three patients, JABR improved or remained the same post-surgery. In the three patients whose JABR remained at one (all with multiple joint arthropathy), post-surgery bleeds were mostly at non-operated sites. Two of the three patients whose JABR increased post-surgery had undergone surgery for reasons unlikely to improve JABR. Mobility parameters often improved in patients whose JABR remained at zero. CONCLUSION: Patients with haemophilia treated with N8-GP prophylaxis benefit from surgeries. However, this analysis could not differentiate the relative contributions of surgical interventions and prophylactic treatment to the improvement of JABR.

Post-hoc analysis on the long-term response to fixed-dose prophylaxis with N8-GP in patients with haemophilia A.

INTRODUCTION: Challenges with personalised prophylaxis in haemophilia remain, including designing unique dosing schedules that require continual adjustments and monitoring using complex sampling procedures. AIM: To assess long-term efficacy and pharmacokinetic outcomes with fixed-dose N8-GP prophylaxis. METHODS: Descriptive analyses were performed on data from the pathfinder 2 and pathfinder 5 trials of patients with severe haemophilia A. Bleed frequency and reoccurrence were assessed in relation to several clinical criteria of interest. Bleed risk relative to time since last dose was assessed using calculated annualised bleeding rate (ABR). Long-term ABR and mean factor VIII (FVIII) trough levels were assessed in patients who received consistent N8-GP prophylaxis every 4 days (Q4D). RESULTS: During pathfinder 2, 117/136 patients with study-drug exposure of ≥600 days experienced bleeding episodes; 8.6% of bleeds were reoccurring bleeds; bleed reoccurrence decreased over time. For patients who received consistent Q4D prophylaxis across the trial (n = 61), mean ABR decreased from 3.5 bleeds/year (Year 1) to 1.6 bleeds/year (Year 6); mean FVIII trough levels stabilised at approximately 5% (Year 6). Across patients who received prophylaxis at some point during pathfinder 2 (n = 177), 125/126 (99%) reoccurring bleeds were joint bleeds. For patients receiving Q4D prophylaxis, bleeding risk generally increased as the time since the last prophylaxis dose increased. A similar reduction in ABR and stabilisation of trough level was observed in pathfinder 5. CONCLUSION: Long-term exposure (> 5 years) to fixed-dose N8-GP prophylaxis resulted in a protective haemostatic effect, with reduction in bleed frequency and reoccurrence, and stabilisation of FVIII trough level over time.

Laboratory coagulation tests and recombinant porcine factor VIII: A United Kingdom Haemophilia Centre Doctors' Organisation guideline.

INTRODUCTION: Acquired haemophilia A (AHA) is a rare bleeding disorder caused by development of auto-antibodies to endogenous coagulation factor VIII (FVIII). Recombinant porcine factor VIII (rpFVIII) is currently licensed only for the management of bleeding in patients with AHA. Regular monitoring of rpFVIII is recommended to assess treatment effectiveness. AIM: This guideline from the United Kingdom Haemophilia Centre Doctors' Organisation (UKHCDO) examines the current publications in the area and aims to offer advice for the laboratory monitoring of rpFVIII in patients with AHA. METHODS: A review of the current literature was undertaken followed by critical review by the authors. RESULTS/CONCLUSIONS: A validated one-stage clotting FVIII assay is recommended for the measurement and regular monitoring of rpFVIII. Assessment of cross-reacting rpFVIII inhibitors by one-stage porcine Bethesda assay should be performed as part of the initial diagnosis of AHA or prior to treatment with rpFVIII. Available data show that chromogenic FVIII assays underestimate rpFVIII and this should be considered if measurement of rpFVIII is required in patients receiving Emicizumab.

Examining patient and professional perspectives in the UK for gene therapy in haemophilia.

INTRODUCTION: With the development of gene therapy for people with haemophilia (PWH), it is important to understand how people impacted by haemophilia (PIH) and clinicians prioritise haemophilia treatment attributes to support informed treatment decisions. OBJECTIVE: To examine the treatment attribute preferences of PIH and clinical experts in the United Kingdom (UK) and to develop a profile of gene therapy characteristics fit for use in future discrete choice experiments (DCEs). METHODS: Semi-structured interviews were conducted with PIH (n = 14) and clinical experts (n = 6) who ranked pre-defined treatment attributes by importance. Framework analysis was conducted to identify key themes and treatment attributes; points were allocated based on the rankings. Synthesis of results by a multidisciplinary group informed development of a profile of gene therapy characteristics for use in future research. RESULTS: Key themes identified by PIH and clinical experts included patient relevant features and the importance of 'informed decision making'. The six top-ranked treatment attributes were 'effect on factor level' (79 points), 'uncertainty regarding long-term risks' (57 points), 'impact on daily life' (41 points), 'frequency of monitoring' (33 points), 'impact on ability to participate in physical activity' (29 points), and 'uncertainty regarding long-term benefits' (28 points). The final treatment characteristics were categorised as therapeutic option, treatment effectiveness, safety concerns, impact on self-management and quality of life (role limitations). CONCLUSION: We identified several gene therapy characteristics important to PIH and clinicians in the UK. These characteristics will be used in a future DCE to further investigate patient preferences for gene therapy.

Oral treatment for mucopolysaccharidosis VI: Outcomes of the first phase IIa study with odiparcil.

Mucopolysaccharidosis (MPS) disorders are a group of rare, progressive lysosomal storage diseases characterized by the accumulation of glycosaminoglycans (GAGs) and classified according to the deficient enzyme. Enzyme replacement therapy (ERT) of MPS VI has limited effects on ophthalmic, cardiovascular, and skeletal systems. Odiparcil is an orally available small molecule that results in the synthesis of odiparcil-linked GAGs facilitating their excretion and reducing cellular and tissue GAG accumulation. Improve MPS treatment was a Phase 2a study of the safety, pharmacokinetics/pharmacodynamics, and efficacy of two doses of odiparcil in patients with MPS VI. The core study was a 26-week, randomized, double-blind, placebo-controlled trial in patients receiving ERT and an open-label, noncomparative, single-dose cohort not receiving ERT. Patients aged ≥ 16 years receiving ERT were randomized to odiparcil 250 or 500 mg twice daily or placebo. Patients without ERT received odiparcil 500 mg twice daily. Of 20 patients enrolled, 13 (65.0%) completed the study. Odiparcil increased total urine GAGs (uGAGs), chondroitin sulfate, and dermatan sulfate concentrations. A linear increase in uGAG levels and odiparcil exposure occurred with increased odiparcil dose. Odiparcil demonstrated a good safety and tolerability profile. Individual analyses found more improvements in pain, corneal clouding, cardiac, vascular, and respiratory functions in the odiparcil groups vs placebo. This study confirmed the mechanism of action and established the safety of odiparcil with clinical beneficial effects after only a short treatment duration in an advanced stage of disease. Further assessment of odiparcil in younger patients is needed.

Dosing for Personalized Prophylaxis in Hemophilia A Highly Varies on the Underlying Population Pharmacokinetic Models.

BACKGROUND: Model-informed personalized prophylaxis with factor VIII (FVIII) replacement therapy aimed at higher trough levels is becoming indispensable for patients with severe hemophilia A. This study aimed to identify the most suitable population pharmacokinetic (PK) models for personalized prophylaxis using various FVIII products and 2 clinical assays and to implement the most suitable one in open-access software. METHODS: Twelve published population PK models were systematically compared to predict the time above target (TaT) for a reference dosing occasion. External validation was performed using a 5-point PK data from 39 adult patients with hemophilia A with FVIII measured by chromogenic substrate (CSA) and 1-stage assays (OSAs) using NONMEM under 3 different conditions: a priori (with all FVIII samples blinded), a posteriori (with 1 trough sample), and general model fit (with all FVIII samples including the reference dosing occasion provided). RESULTS: On average, the baseline covariate models overpredicted TaT (a priori; bias -3.8 hours to 49.6 hours). When additionally including 1 previous trough FVIII sample before the reference dosing occasion (a posteriori), only 50% of the models improved in bias (-1.0 hours to 36.5 hours) and imprecision (22.4 hours and 60.7 hours). Using all the time points (general model fit), the models accurately predicted (individual TaT less than ±12 hours compared with the reference) 62%-90% and 33%-74% of the patients using CSA and OSA data, respectively. Across all scenarios, predictions using CSA data were more accurate than those using the OSA data. CONCLUSIONS: One model performed best across the population (bias: -3.8 hours a priori, -1.0 hours a posteriori , and 0.6 hours general model fit ) and acceptably predicted 44% (a priori) to 90% ( general model fit ) of the patients. To allow the community-based evaluation of patient-individual FVIII dosing, this model was implemented in the open-access model-informed precision dosing software "TDMx."

The effect of SARS-Co-V2 infection on prothrombotic and anticoagulant factors in dialysis patients.

BACKGROUND: Patients with COVID-19 infection are at increased risk of thrombosis. We wished to determine whether this was is due to an increase in prothrombotic or reduction in anticoagulant factors and whether heparin would be an appropriate anticoagulant. METHODS: We measured routine coagulation and prothrombotic factors in dialysis patients after a positive COVID-19 test between March 2020 -April 2021. RESULTS: Routine coagulation tests were measured in 227 dialysis patients, 148 males (65.2%), median age 67.5 (53.8-77.0) years. The international normalized ratio was prolonged in 11.5%, activated partial thromboplastin time in 48.5%, thrombin time in 57%. Factor VIII was increased in 59.1%, fibrinogen 73.8%, and D-dimer 95.5%. Protein C was reduced in 15.3%, protein S 28%, and antithrombin (AT) in 12.1%. Two patients were Lupus anticoagulant positive, and two Factor VLeiden positive. Factor VIII levels increased with clinical disease; outpatients 159 (136-179) IU/dl, hospitalized but not ventilated 228 (167-311) IU, ventilated 432 (368-488) IU/dl (p < 0.01). Overall 75% had an AT level ≥ 88 IU/dl (reference range 79-106), but only 11.7% of non-hospitalized patients compared to 45% of those who died, p < 0.01, fibrinogen, D-dimers, and protein S or C did not differ with clinical disease severity, whether patients required hospital admission or not and between survivors and those who died. CONCLUSION: COVID-19 dialysis patients have increased levels of fibrinogen and D-Dimers, but only factor VIII levels in the clotting profile increased with clinical disease severity increasing systemic hypercoagulability. AT concentrations are maintained and as such should not compromise anticoagulation with heparins.

Subcutaneous concizumab prophylaxis in hemophilia A and hemophilia A/B with inhibitors: phase 2 trial results.

Results from the main parts (24 weeks) of 2 concizumab phase 2 trials are presented: explorer4 in hemophilia A (HA) or B (HB) with inhibitors (HAwI/HBwI) and explorer5 in HA. The trials aimed to evaluate the efficacy of daily subcutaneous concizumab prophylaxis (evaluated as annualized bleeding rate [ABR] at last dose level), with secondary objectives being safety and immunogenicity (assessed as number of adverse events [AEs] and antidrug antibodies [ADAs]). Patients received 0.15 mg/kg concizumab, with potential dose escalation to 0.20 and 0.25 mg/kg (if ≥3 spontaneous bleeding episodes within 12 weeks of concizumab treatment). Relevant pharmacokinetic/pharmacodynamic (PK/PD) parameters were assessed. Thirty-six HA, 9 HAwI, and 8 HBwI patients were exposed to concizumab. Most inhibitor patients (15 of 17; 88.2%) did not escalate the dose; all patients chose to continue to the extension phase of the trials. Clinical proof of concept for prevention of bleeding episodes was demonstrated in both trials. Estimated ABRs in HAwI and HBwI were lower vs HA: 3.0 (95% confidence interval [CI], 1.7; 5.3) and 5.9 (95% CI, 4.2; 8.5) vs 7.0 (95% CI, 4.6; 10.7), respectively. PK/PD results were as expected, with no difference between hemophilia subtypes for concizumab exposure, free tissue factor pathway inhibitor, thrombin generation, prothrombin fragment 1+2, and d-dimers. Concizumab was safe and well tolerated (no severe AEs, AE-related withdrawals, or thromboembolic events). Three patients had (very low to medium titer) ADA+ tests in each trial, with no observed clinical effect. These results support further development of concizumab as a daily prophylactic treatment in all hemophilia patients. These trials were registered at www.clinicaltrials.gov as #NCT03196284 and #NCT03196297.

Delivery of AAV-based gene therapy through haemophilia centres-A need for re-evaluation of infrastructure and comprehensive care: A Joint publication of EAHAD and EHC.

INTRODUCTION: Adeno-associated virus (AAV)-based gene therapy for haemophilia presents a challenge to the existing structure of haemophilia centres and requires a rethink of current collaboration and information exchange with the aim of ensuring a system that is fit-for-purpose for advanced therapies to maximise benefits and minimise risks. In Europe, a certification process based on the number of patients and facilities is offered to the haemophilia centres by European Haemophilia Network (EUHANET). AIM AND METHODS: This joint European Association for Haemophilia and Allied Disorders (EAHAD) and European Haemophilia Consortium (EHC) publication describes criteria for centres participating in gene therapy care that require a reassessment of the infrastructure of comprehensive care and provides an outlook on how these criteria can be implemented in the future work of haemophilia centres. RESULTS: The core definition of a haemophilia treatment centre remains, but additional roles could be implemented. A modifiable 'hub-and-spoke' model addresses all aspects associated with gene therapy, including preparation and administration of the gene therapy product, determination of coagulation and immunological parameters, joint score and function, and liver health. This will also include the strategy on how to follow-up patients for a long-term safety and efficacy surveillance. CONCLUSION: We propose a modifiable, networked 'hub and spoke' model with a long term safety and efficacy surveillance system. This approach will be progressively developed with the goal of making haemophilia centres better qualified to deliver gene therapy and to make gene therapy accessible to all persons with haemophilia, irrespective of their country or centre of origin.

Challenges of antithrombotic therapy in the management of cardiovascular disease in patients with inherited bleeding disorders: A single-centre experience.

INTRODUCTION: Cardiovascular events in patients with inherited bleeding disorders are challenging to manage. The risk of bleeding secondary to antithrombotic treatment must be balanced against the risk of thrombosis secondary to haemostatic therapy. METHODS: Patients with inherited bleeding disorders with coronary artery bypass grafting (CABG), percutaneous coronary intervention (PCI) or atrial fibrillation (AF) from a single centre (2010-2018) are included. RESULTS: A total of 11 patients undergoing CABG (n = 3), PCI (n = 5) or with AF (n = 3) and a diagnosis of haemophilia A (n = 8), haemophilia B (n = 1), factor XI deficiency (n = 1) and von Willebrand disease (n = 1) managed by a multidisciplinary team are reported. In patients undergoing CABG, factor levels were normalized for 7-10 days with trough levels of 70-80% with severe patients continuing high-dose factor prophylaxis (trough 20-30%) three weeks post-operatively with daily aspirin. In a patient with mild haemophilia A and an inhibitor, recombinant factor VIIa dosing was monitored with thromboelastometry. For PCI, a 3rd-generation drug-eluting stent with one month of dual antiplatelet therapy in addition to high-dose prophylaxis as needed was preferred. Patients with AF and severe haemophilia did not receive antithrombotic treatment, and a thrombin generation assay was used to guide heparin dosing in mild haemophilia. CONCLUSION: Our experience demonstrates the importance of interdisciplinary communication to identify strategies that decrease the risk of bleeding and thrombosis. The use of extended, increased intensity prophylaxis facilitated antiplatelet therapy. Global assays may help balance the intensity of haemostatic and antithrombotic treatment.